Originally carpenters hung doors at the work site but over the past few decades there have been various machines developed to facilitate the machining and assembly of pre-hung doors. This function is now performed generally by Millwork and Specialty firms. The process includes preparing the door, jamb and other members by routing or mortising for hinges, drilling generally for a cylindrical type lock, attaching the hinges with screws, and nailing up the frame around the door. My invention relates specifically only to the special aspect of attaching the hinges. This has been a tedious and time consuming job if done manually. My invention claims a higher degree of automation than previously attained especially relating to hinge feeding with some notable improvements in other areas. Various considerations have been adopted relating to hinge application, the most notable and closely related known to the inventor is as follows:
U.S. Pat. No. 4,100,661 to Edward G. Cheak, provides for machining pre-hung door members, pre-drilling screw holes and attaching hinges without the use of automatic screw or hinge feeding.
U.S. Pat. No. 3,979,817 to Edward G. Cheak method claims of Cheak patent.
U.S. Pat. Nos. 4,837,916, 4,839,957, and 4,782,588 to Erling S. Jangaard describes a mechanism for automatic screw feeding, manual hinge feeding, and power means to drive screws.
All of the foregoing patents and U.S. Pat. No. 3,889,343 to Miller et al. and U.S. Pat. No. 3,772,757 to Goldstein as well, each describe hinge applicators which utilize a gang screwdriving unit for simultaneously driving the screws into the hinge. The screwdrivers are powered for rotation by a gearing system that uses a common power source or, in the case of U.S. Pat. No. 3,889,343, by an independent fluid motors for each screwdriver. The screwdrivers are fixed to a carriage which is first moved from a retracted position to a forward position to engage the screws to be driven. To simultaneously drive the screws the carriage is then urged farther forward as each screwdriver is rotated.
U.S. Pat. No. 3,339,601 to Carl E. Christman and Thomas S. Ferguson discloses an automatic work bench adapted for applying door knobs as well as hinges. The hinge attaching features are not separately claimed.
U.S. Pat. No. 4,785,531 to Armand E. Roy and Leo T. Roy demonstrates the application and placement of an easel type hinge in a specific manner.
U.S. Pat. No. 3,071,291 to Charles Alfred Davis applies to nailing machines for automatic feeding of nails rather than screws. It utilizes a separate oscillating hopper box to shake screws down a fixed slide assembly.
U.S. Pat. No. 2,943,764 to Alfred H. Haberstump uses an oscillating hopper box also with a fixed screw slide escapement assembly.
Although there are a number of patents relating to the general area of machine construction for the purpose of producing pre-hung doors, my invention has many novel features and none of these patents disclose nor claim an automatic hinge handling of positioning device such as found in my invention.